US FDA now joins in probe of Sanofi's Multaq safety

The US Food and Drug Administration says it is reviewing data from a clinical trial that was evaluating the effects of French drug major Sanofi’s (Euronext: SAN) antiarrhythmic drug Multaq (dronedarone) in patients with permanent atrial fibrillation.

The study, dubbed PALLAS, was stopped early after the data monitoring committee found a two-fold increase in death, as well as two-fold increases in stroke and hospitalization for heart failure in patients receiving Multaq compared to those given a placebo (The Pharma Letter July 8). This led to the European Medicines Agency broadening its investigation of Multaq and Canadian regulators doing likewise (TPL July 12). The drug was already being probed by the EMA for potential liver injury and failure risks.

Currently Multaq, which generated 2010 revenues of around $246 million and about $90 million in the first quarter of this year, is approved for use in a different, but related patient population. The drug had been touted as having a sales potential of more than $4 billion, but early uptake has been disappointing. The approval of Multaq was based on another trial (ATHENA) in which use of Multaq was associated with a decreased number of deaths compared to placebo.